A former deputy environmental protection minister in China is under investigation for alleged corruption. The Communist Party's anti-graft agency said in a statement that Zhang Lijun had been detained for serious violations of party discipline and law, the form of words it regularly uses to describe corruption. Zhang is the first senior official, or “tiger”, working in environmental protection to come under investigation for graft under the government’s huge anti-corruption campaign. President Xi Jinping pledged to go after “tigers and flies” – high and low-ranking officials – when he launched the anti-graft campaign after taking power three years ago. The statement from anti-graft agency, the Central Commission for Discipline Inspection, gave no details of the allegations against Zhang. He worked in environmental protection for more than 20 years, serving as the deputy minister from 2008 to 2013. The anti-graft commission earlier this year strongly criticised the system for carrying out environmental risk assessments. Inspectors found that some government officials had profited by running risk-assessment agencies or that their relatives had intervened to influence the outcome of reviews. The CCDI did not name guilty officials, but said the review system was flawed and needed to be reformed. News that Zhang, 63, is under investigation came after the revelation that a letter of complaint about him had been sent to the CCDI by a mainland environment news reporter. The 2014 letter, written by Song Yangbiao, who works for the Guangzhou-based Time Weekly , had accused Zhang and several other senior ministry officials of soliciting illicit profits by manipulating the state environment standards that govern vehicle emissions. Song's claims included allegations that emission-testing equipment standards were adapted for the benefit of a well-connected Shenzhen-based contractor, and also that bribes were accepted in return for agreeing to add carmakers' vehicle models to lists that stated the vehicles had passed stringent new emissions standards. According to his public profile, Zhang, 63, had worked in the field of environmental protection for more than 20 years, starting off as the local chief of Jilin’s environmental protection bureau in 1989. After serving as editor-in-chief of the newspaper, China Environment News , for about five years, Zhang led several of the ministry’s crucial and powerful departments, including those of planning and finance and pollution prevention and control. He retired in 2013 and was replaced by Zhai Qing, 51, who has also led the same two departments at the ministry. In March anti-graft authorities said Liu Xiangdong, former head of the environmental protection department in the province of Shanxi was being investigated for alleged corruption. He was accused of granting environmental permits to mining projects in return for cash, the news website Thepaper.cn reported, citing an unnamed source.